A relay node (RN), or relay station (RS), or simply relay, is considered as a tool to improve, e.g., the coverage of a base station, group mobility, temporary network deployment, the cell-edge throughput and/or to provide coverage in new areas. The RN is wirelessly connected to a wireless communications network via a donor cell (also referred to as a donor enhanced Node B (donor eNB or DeNB)) through network resources donated (i.e., allocated) by the DeNB. The DeNB serves the RN as if the RN is a UE.
A wireless connection between an RN and its DeNB may be referred to as a backhaul link or a Un link. To User Equipment (UE) that is being served by the RN, the RN may appear to be an eNB, scheduling uplink (UL) and downlink (DL) transmissions for the UE over an access link between the RN and the UE. The access link between an eNB and a UE, or between an RN and a UE may also be referred to as a Uu link.
In a communications system, when a network node experiences congestion, data packets may be dropped by the congested network node in an attempt to reduce congestion. Furthermore, an end-to-end congestion control mechanism in a transport layer protocol, such as the Tahoe or Reno algorithm in Transmission Control Protocol (TCP), may cause a sender to reduce a source data rate (often significantly) in response to an indication of a lost packet from a recipient to further alleviate congestion.
In a radio access network (RAN), an eNB (also commonly referred to as a base station, Node B, access network, access point, controller, communications controller, and so forth) may drop data packets in the DL when congestion occurs on the DL at the eNB.
However, due to an inherent uncertainty in wireless communications, it may be hard to determine if a packet has been dropped intentionally or lost in transmissions due to poor operating conditions. Therefore, there is a need for a system and method for monitoring dropped packets in wireless communications.